January 2023
· 4 min read
This revision updated language regarding odor and color in Section 8.4.2.4.
This revision updates language in Sections 6.1, 6.2.2, and Annex I-2 to bring it in line with NSF’s publishing guidelines. It also removes the word “NOTE” from Section 8.5.1.2 to make it clear that the language is a requirement of the standard.
This revision incorporates clarifications into Section 8 regarding influent wastewater characteristics that previously existed in an interpretation request.
This revision adds Normative Annex 1: Approval of scaling and alternate system configurations to provide guidance on scale up.
This revision adds language regarding effluent pH in Section 8.5.2.1.3. The language requires NSF 40 tests meet an average pH range for influent and effluent.
This revision updates language in Section 5.8 to harmonize the audible and visual alarm requirements between NSF/ANSI 40, NSF/ANSI 245, and NSF/ANSI 350.
This revision updated the normative references in Section 2.
This revision removes the definitions from the Wastewater Technology suite of standards and instead references the newly adopted NSF/ANSI 437: Glossary of Wastewater Technology Terminology.
This revision modifies language in Section 8.2.2.2 to harmonize stress loading language among the suite of Wastewater Standards. The new language requires that stress loading events are performed in the order specified in the standard and adds a week tolerance to when stress loading sequences begin. This change will have a deadline for compliance of January 1, 2024.
This revision updates the normative references in Section 2.
This revision clarifies language regarding the pass/fail criteria for nitrogen removal in Section 8.4.3.3.
This revision updates language in Section 5.8 to harmonize the audible and visual alarm requirements between NSF/ANSI 40, NSF/ANSI 245, and NSF/ANSI 350.
This revision further updates the normative references in Section 2.
This revision removes the definitions from the Wastewater Technology suite of standards and instead references the newly adopted NSF/ANSI 437: Glossary of Wastewater Technology Terminology.
This revision modifies language in Section 8.2.2.2 to harmonize stress loading language among the suite of Wastewater Standards. The new language requires that stress loading events are performed in the order specified in the standard and adds a week tolerance to when stress loading sequences begin. This change will have a deadline for compliance of January 1, 2024.
This revision adds a noise correction chart to Section 5.4.
This revision updates the requirements for bypass alarms in Section 5.8. The language removes the requirement for a bypass alarm on systems that divert surplus water to a bypass as part of normal operation.
This revision modifies timing for grab samples in NSF/ANSI 350, adding an option to collect grab samples during morning or noon dosing period for gravity flow systems under Section 8.4.3.
This revision updates language in Section 8.1.2.2.1.1 to add clarity regarding combined Class C and Class R system testing based on a submitted interpretation request.
This revision adds clarity to Table N-1.1 by replacing dashes within some of the cells with “NA”.
This revision updates language regarding color, odor, oil film, and foam in Sections 8.5 and 8.6 in order to harmonize these sections with their counterpart sections in NSF/ANSI 40.
This revision updates Tables N-1.1 and N-1.2 to remove analyses that have been removed from the requirements of the standard.
This revision adds references for Sections 8.2.1.8 and 8.5.2 in Section 5.11 to add additional clarity to the language.
This revision updates language in Section 5.8 to harmonize the audible and visual alarm requirements between NSF/ANSI 40, NSF/ANSI 245, and NSF/ANSI 350.
This revision removes the requirement in Section 1.2 for systems certifying to NSF/ANSI 350 to also meet the requirements of NSF/ANSI 40, and removes the latter as a normative reference.
This revision affirms the addition of language allowing disinfection devices such as tablet or liquid chlorinators to be periodically refilled with disinfectant during testing in NSF/ANSI 350.
This revision removes the definitions from the Wastewater Technology suite of standards and instead references the newly adopted NSF/ANSI 437: Glossary of Wastewater Technology Terminology.
This revision updates normative references in NSF/ANSI 350.
This revision revises a section heading in Section 5.10 of NSF/ANSI 350.
This revision modifies language in Section 8.2.2.2 to harmonize stress loading language among the suite of Wastewater standards. The new language requires that stress loading events are performed in the order specified in the standard and adds a week tolerance to when stress loading sequences begin. This change will have a deadline for compliance of January 1, 2024.
This revision adds language regarding commercial applications to address systems installed in commercial settings such as office buildings.